What does “gut health” really mean?
Before we dive in, there are a few definitions we need to know. You might hear gut flora, and you might hear gut microbiota. Flora refers to bacteria only, while microbiota may refer to the bacteria, archea, fungi, and viruses that live in the human gut. Oh, I also shouldn’t forget to mention that by gut, I mean the human gastrointestinal tract.
I came across a great review on the role of gut bacteria in human health and disease, and I will be using that primarily to write this blog. You can find it here if you’d like to read further into detail.
Imagine how complex the human body is. Try to imagine all of the different processes occurring in your body right now. Cellular processes happen on their own, and thankfully we don’t even have to think about them in order for them to occur. Now, imagine how many cells you have in your body doing all this work. To imagine the amount of bacteria in your body, multiply that by 10… yes, 10… and that’s only in your gut! The gut has 10 times more bacteria in it than human cells in your entire body. That alone is wild to me. Common sense tells me that if those bacteria aren’t happy, then your body won’t be happy, but let’s keep investigating.
Something that you might find when researching gut health is that the field is relatively new, so knowledge is more limited than we would like it to be, but not any less interesting!
One of the most interesting thing to consider is that your gut bacteria makeup is unique to you. Your gut bacteria makeup is like a snowflake; no two people have the same composition of gut bacteria. You have between 300 and 500 bacteria species living inside your gut, so any combination or permutation of these species is possible, but researchers say there are three main kinds, or enterotypes.
Your gut microbiota aren’t necessarily specific to your sex, age, weight, or nationality, but they do change from when you’re a newborn to when you’re older. They also depend on what you eat. Additionally, the type of bacteria you might see depends on their exact location within the gut. This makes sense – each bacteria is suited for its environment and its role in the body, and not every location in the gut is the same.
It seems like the most simple way to think about gut health is the interaction between us and our gut bacteria. They clearly serve a great purpose, so let’s dive into what these purposes might be!
What is the purpose of gut bacteria?
Well, this answer is still under investigation, but I will summarize what has been found so far. The findings might surprise you because they surprised me. I had no idea just how much help that bacteria give us. Quite frankly, we could not survive without them.
There are 3 main functions that gut bacteria take on – metabolic, trophic, and protective.
Metabolic. Your gut bacteria help you get more nutrients out of your food, and they help produce different fatty acids and amino acids, which both play vital roles in nutrient transport and metabolism (duh, metabolic). They also provide your body with micronutrients like Vitamin K and folic acid (Vitamin B9).
Trophic. Trophic means “related to feeding or nutrition” (Oxford), or more specifically, growth. The inner lining of your digestive tract is made up of special cells (epithelial cells). Your gut bacteria help these to multiply and grow into other types of cells. Additionally, this trophic effect of the bacteria helps your immune system develop and remain stable. This is truly amazing – your body and your bacteria talk to one another so that your immune system is functioning properly.
Protective. Your gut bacteria have a barrier effect on your body, protecting it from potential pathogens. Good bacteria out-compete bad bacteria in your gut, keeping you healthy and free from infection. When you get a bacterial infection, the bad bacteria have out-competed the good bacteria, as I’m sure you know.
How to promote gut health
Several review articles link an imbalance of gut bacteria to diseases such as inflammatory bowel disease and irritable bowel syndrome. There is also a suspected link between diseases like obesity, metabolic syndrome, nonalcoholic fatty liver disease, and nonalcoholic steatohepatitis and imbalances or improper location of certain bacteria in the gut.
It’s quite obvious at this point that we want our guts to be happy so that the bacteria can help us out in the best way possible. According to current research, how can we do this?
This is where probiotics and prebiotics come into play.
Probiotics. Probiotics are live organisms that you can either take as a supplement or get from fermented foods. It’s important to understand that there are many different strains of bacteria, each with specific functions. Rather than giving you a list of them all, I will simply state again that each person has different gut bacteria makeups, so different probiotics might suit different people for different purposes. The research shows that introducing probiotics into the gut can help with certain diseases and disorders, and there is no colonization by the introduced strain. This means that if you take a certain strain, it won’t out-compete your bacteria that is already established.
Prebiotics. Prebiotics are not live organisms like probiotics, but rather they are food for the bacteria in your gut. These are considered nondigestible food ingredients. Does fiber ring a bell? One prebiotic that has proven efficacy in promoting a healthy balance of gut bacteria is inulin, and you can buy this at the grocery store in the form of a supplement. It is soluble fiber and is found in powder form.
Again, the field is relatively new, and because there are so many different strains of bacteria, it’s hard to pinpoint the specifics in terms of the exact health benefits. However, from my overview of the literature, it looks like bacteria are our friends, but we don’t want to cause imbalances.
It looks like it’s very helpful to take probiotics and prebiotics, and a healthy diet will help maintain a healthy gut!
My take on gut health from a nutrition perspective
Our gut health plays an important role in health and disease. Additionally, a nutrient-poor diet is linked to an imbalance of gut bacteria, which may lead to various diseases. What is the primary thing that you put into your gut? FOOD… I hope at least.
While all the nitty gritty details of gut health still aren’t fully understood, there appears to be a strong link between eating healthy, gut health, and overall health. If you aren’t giving your body nutritious foods, how can you expect it to function properly?
If you have been following me for a while now, you know that I stress the importance of getting enough fiber and micronutrients in your diet. It appears that these two factors are key in keeping a happy gut, and in turn, your gut can protect you and help maintain your health.
Finally, given that everyone’s gut microbiota is different, the same probiotic/prebiotic supplement might help someone but not someone else, especially because they are preformulated and not individually tailored. I take a probiotic to help my acne, and it also mysteriously made my nails grow long and strong. I found some research that shows that certain bacteria strains produce collagen, so maybe this is why?
Remember, as I always say, read into everything before you spend your money, invest your time, or risk your health on anything! Knowledge is power. Ask questions. Stay skeptical!
If you liked this blog post, hit the subscribe button to get notified of when I post next! I love educating and learning while I do so. The next several posts will discuss the basics of nutrition, and we just learned how proper nutrition will lead to a happy gut, which leads to a plethora of health benefits! Stay tuned!
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References for further reading
- Quigley EM. Gut bacteria in health and disease. Gastroenterol Hepatol (N Y). 2013 Sep;9(9):560-9. PMID: 24729765; PMCID: PMC3983973.
- Francisco G. & Malagelada J-R., Gut flora in health and disease. The Lancet, 2003 361(9356):512-519
- Arumugam, M., Raes, J., Pelletier, E. et al. Enterotypes of the human gut microbiome. Nature 473, 174–180 (2011). https://doi.org/10.1038/nature09944
- Tuohy K. M., Probert H. M., Smejkal C. W., Gibson, G. R. Using probiotics and prebiotics to improve gut health, Drug Discovery Today, 2003 8(15):692-700
P. S. – I’m sorry that these are all in different formats!